1. Field of the Invention
The present invention relates to a device and a method for recovering developer medium. More particularly, the device and the method of the present invention absorb only the developer medium which is dispersed in toner images on a photoreceptor, by an image dryer in a color laser printer which forms multi-color images by a wet type electrophotographic recording technology. Moreover, the present invention relates to a device and a method for recovering developer medium by using a cooling device that cools and then liquefies the developer medium vaporized at an image drier.
2. Description of the Related Art
FIGS. 1 and 2 are a perspective view and a cross-sectional view of a conventional vapor recovery device of developer medium, respectively.
This conventional vapor recovery device of developer medium has a metal mesh 206 at the bottom of capacitor columns 207, and delivers vaporized developer medium below the metal mesh 206 through pipes that constitute inlet ports 202 at the center of the capacitor columns 207. When an electrophotographic device is started, an initial developer medium is supplied from a supply port 210 into the capacitor columns 207. The quantity of the developer medium increases as the vaporized developer medium is liquefied, and overflows to the outside from the capacitor columns 207 through a recovery port 208.
To an outside wall of the capacitor columns 207, a Peltier element 205 is connected to cool the developer medium. A heat sink 204 is connected to the Peltier element 205, and a cooling fan 203 is mounted onto the heat sink 204 for cooling.
In the conventional vapor recovery device of developer medium shown in FIGS. 1 and 2, the metal mesh 206 is used to generate bubbling (subdividing the vaporized developer medium into bubbles in the developer medium). Moreover, liquefaction efficiency by bubbling is controlled by providing a plurality of partition panels 209 having about 50 holes of about 1 mm in diameter inside the capacitor columns 207. In this case, liquefaction efficiency is low, considering the high pressure loss. Thus, the gas quantity of vaporized developer medium passing through each capacitor column 207, must be suppressed without choice, and the device is significantly large having many parts in which quadruple capacitor columns 207 are joined as shown in FIG. 1.
The conventional vapor recovery device of developer medium shown in FIGS. 1 and 2 has the following problems.
Liquefaction efficiency is low, considering the high pressure loss.
In order to obtain constant liquefaction efficiency, the gas quantity of vapor passing through each capacitor column has to be suppressed to several liters per minute. As a result, the capacitor has to have a quadruple multi-column structure as shown in FIG. 1.
As shown in FIG. 2, the bubbling mechanism is complex, and the unit and electric power use are also large. Particularly, when the capacitor columns are shorter than a certain length, liquid will flow out of the capacitor.
The liquid temperature of preliminarily stored developer medium has to be decreased to about 5xc2x0 C. so as to maintain liquefaction efficiency. As a result, the water contained in the vaporized developer medium is condensed inside the capacitor columns, and recovered developer cannot be reused. Moreover, the wattage of the Peltier element has to be large enough to allow liquid temperature to decrease to around 5xc2x0 C. when the power is turned on.
Additionally, this process is time consuming.
Accordingly, it is an object of the present invention to selectively liquefy vaporized developer medium, and to remove moisture from recovered developer medium for reuse without liquefying water vapor.
It is another object of the present invention to improve liquefaction efficiency of vaporized developer medium.
According to an aspect of the present invention, a vapor recovery device of developer medium is provided. The vapor recovery device has a capacitor column that can store the developer medium at the bottom, air stones provided at the bottom of the capacitor column, a suction port to transmit vaporized developer medium to the bottom of the air stones, and a cooling device to cool the developer medium inside the capacitor column and the vaporized developer medium to a constant temperature.
According to another aspect of the present invention, a vapor recovery device of developer medium is provided.
The vapor recovery device has a capacitor column that can store the developer medium at the bottom, air stones provided at openings of a partition plate at the bottom of the capacitor column, a capacitor base which is attached to the bottom of the partition plate at the periphery thereof and has a hollow section below the air stones and partially below the partition plate, a suction port which is provided at an inner surface of the hollow section to transmit vaporized developer medium toward the bottom of the partition plate having no air stones, and a cooling device to cool the developer medium in the capacitor column and the vaporized developer medium to a constant temperature.
According to still another aspect of the present invention, a vapor recovery device of developer medium is provided that absorbs only the developer medium scattered in toner images on a photoreceptor of an electrophotographic device by an image dryer and recovers vaporized developer medium. The vapor recovery device has a capacitor column that can store the developer medium at the bottom, air stones provided at the bottom of the capacitor column, a suction port to transmit the vaporized developer medium to the bottom of the air stones, a cooling device to cool the developer medium in the capacitor column and the vaporized developer medium to a constant temperature, a suction device to suck the vaporized developer medium inside the capacitor column and transmit it into a shell space having the photoreceptor and the image drier inside, a pipe which connects the image drier to the suction port to transmit the vaporized developer medium absorbed by the image drier to the suction port, and a recovery device to transmit the developer medium inside the capacitor column by an additional amount which is greater than an initial constant liquid level and thus overflows, to a developer medium storing section.
According to yet another aspect of the present invention, a vapor recovery method of developer medium is provided. The developer medium is stored at the bottom of a capacitor column having air stones at the bottom, and vaporized developer medium is transmitted to the bottom of the air stones, thus subdividing the vaporized developer medium into bubbles in the developer medium inside the capacitor column for cooling and liquefying.
Furthermore, according to the present invention, a vapor recovery method of developer medium is provided. The method includes the steps of transmitting developer medium by a quantity greater than an initial constant liquid level into a capacitor column which can store the developer medium at the bottom, by operating a supply device as an electrophotographic device is started, cooling the developer medium stored in the capacitor column and the vaporized developer medium to a constant temperature by a cooling device, transmitting the developer medium to a developer medium storage section from the capacitor column by a recovery device while leaving only a quantity of the initial liquid level, transmitting the vaporized developer medium inside the capacitor column by a suction device into a shell space having a photoreceptor of the electrophotographic device and an image drier inside while the electrophotographic device is forming images, sucking the vaporized developer medium absorbed by the image drier into the capacitor column from a suction port below air stones at the bottom of the capacitor column, and starting the recovery device by stopping the suction device at a constant cycle after image forming operations end, thus delivering the developer medium inside the capacitor column into the developer medium storage section while keeping only the quantity of the initial liquid level.